Magnetic filter elements and cigarettes having magnetic filter elements

ABSTRACT

A magnetic cigarette filter element is provided comprising a filter material and at least one magnetic substrate. The magnetic substrate can comprise at least one monolithic ferromagnetic substrate in the shape of a disc, ring, ribbon, mesh, rod, cylinder and/or spheroid that is incorporated in, on and/or around the filter rod. The magnetic substrate can filter (i.e., magnetically attract and trap) ferromagnetic particles from the mainstream smoke of a cigarette comprising the magnetic cigarette filter.

CROSS REFERENCE TO RELATED APPLICATION

This application claims priority under 35 U.S.C. §119(e) to U.S.provisional Application No. 60/787,524, filed on Mar. 31, 2006, theentire content of which is incorporated herein by reference.

BACKGROUND

In the description that follows reference is made to certain structuresand methods, however, such references should not necessarily beconstrued as an admission that these structures and methods qualify asprior art under the applicable statutory provisions. Applicants reservethe right to demonstrate that any of the referenced subject matter doesnot constitute prior art.

U.S. Pat. Nos. 5,191,905; 4,260,523 and 4,258,730 disclose an activecarbon composition that comprises a magnetized material for thecatalytic removal from cigarette smoke of carbon monoxide, hydrogen andthe like. U.S. Pat. Nos. 6,615,843 and 5,468,529 discloses a tobaccosmoke filter composition comprising a magnetic filter material.

The incorporation of nanoscale particle additives (e.g., nanoscalecatalysts) into one or more components of a cigarette is disclosed incommonly-owned U.S. patent application Ser. Nos. 10/460,632; 10/460,631;10/460,303; 10/460,210 and U.S. Patent Publication No. 2003/0075193, thedisclosures of which are hereby incorporated reference. To the extentthat, during the smoking of a cigarette, loose nanoscale particleadditives could possibly be entrained in mainstream smoke, techniques toreduce the amount of nanoscale particle additives in mainstream smokewould be of interest.

SUMMARY

Provided is a filter element adapted to be formed into a cigarette and acigarette comprising the filter element wherein the filter elementcomprises a filter material and at least one magnetic substrate. The atleast one magnetic substrate can filter (via magnetic attraction)ferromagnetic particles from mainstream smoke. Optionally, the at leastone magnetic substrate can change the chemical composition of mainstreamsmoke that flows through the filter element.

Also provided is a method of making a cigarette filter elementcomprising at least one magnetic substrate, comprising (i) providing afilter material and plug wrap material; (ii) incorporating at least onemagnetic substrate in and/or on at least one of the filter material andplug wrap material; and (iii) wrapping the filter material in the plugwrap material to form the filter element.

The magnetic substrate can comprise an electromagnet or a permanentmagnet. In one embodiment the magnetic substrate, which is capable offiltering ferromagnetic particles (e.g., nanoscale iron oxide particles)from the mainstream smoke of the cigarette, consists essentially of amagnetic material selected from the group consisting of ferrite magnets,neodymium iron boron magnets, samarium cobalt magnets, aluminum nickelcobalt magnets and mixtures thereof. The at least one magnetic substratecan have at least one dimension (e.g., length, width and/or thickness)greater than about 1 mm or greater than about 2 mm. Preferably, themagnetic substrate can reduce the amount of ferromagnetic particlesentrained in the mainstream smoke of the cigarette by at least 10%. Themagnetic substrate preferably has a Curie temperature of at least about300° C.

The filter material is selected from the group consisting of celluloseester fibers, regenerated cellulose, polyamide fibers, polyimide fibers,acrylic fibers, polyester fibers, polycarbonate fibers, polyethylenefibers, polyvinyl chloride fibers, filamentary polyolefin materials,polypropylene fibers, wood pulp fibers, cotton, flax, jute, wool, silk,ramie, protein fibers, paper and mixtures thereof. The cigarette filterelement can comprise a mono filter, a dual filter, a triple filter, acavity filter, a recessed filter, a free-flow filter or combinationsthereof.

The at least one magnetic substrate, which can be incorporated in, onand/or around the filter material, can be incorporated into one or morecigarette filter parts selected from the group consisting of a shapedpaper insert, a plug, a space between plugs, cigarette filter paper, acellulose acetate sleeve, a polypropylene sleeve and a free-flow sleeve.Magnetic beads, for example, can be incorporated into filter materialand/or cigarette filter paper by dusting or spraying. A magneticsubstrate can be formed at least partially around the filter material(e.g., a magnetic ring can be formed around the filter material) priorto wrapping the filter material in cigarette paper (e.g., plug wrap).

According to an embodiment, the filter material can be wrapped incigarette paper (e.g., plug wrap) wherein the magnetic substrate isdisposed on an inner surface of the cigarette paper. For example, themagnetic substrate can be adhered to an inner surface of the cigarettepaper with an adhesive. The magnetic substrate can be incorporated inthe filter rod (e.g., incorporated in the filter material) and/orincorporated between the filter rod and the tobacco rod of a cigarette.The distribution of the magnetic substrate throughout the filter elementcan be homogeneous but is preferably non-homogeneous.

The at least one magnetic substrate can comprise a disc, ring, ribbon,mesh, rod, cylinder or spheroid that can be in incorporated in, onand/or around the filter material. Preferably the magnetic substratecomprises a non-porous magnetic material that is at least 50% of itstheoretical density. The magnetic material is preferably sinteredmaterial.

The cigarette filter element can further comprise an adsorbent,flavorant or catalyst and the tobacco rod can further comprise nanoscaleparticles. The resistance to draw through a cigarette filter elementcomprising a magnetic substrate is preferably less than about 5 inchesof water at an air flow velocity of about 1050 cc/min.

Also provided is a method of smoking a cigarette having a filter elementcomprising a magnetic substrate comprising heating or lighting thecigarette to form smoke and drawing the smoke through the cigarettewherein the magnetic substrate filters ferromagnetic particles from themainstream smoke.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a cigarette according to an embodimentwherein magnetic beads are incorporated throughout the filter materialof a filter element.

FIG. 2 is a perspective view of a cigarette according to an embodimentwherein magnetic beads are incorporated within a filter element as a gaspermeable bed.

FIG. 3 is a perspective view of a cigarette according to an embodimentwherein a magnetic ring is around the filter rod of a filter element.

FIG. 4 is a perspective view of a cigarette according to an embodimentwherein magnetic rods are incorporated axially along a surface of thefilter rod of a filter element.

FIG. 5 is a perspective view of a cigarette according to an embodimentwherein a magnetic rod is incorporated axially within the filter rod ofa filter element.

FIG. 6 is a perspective view of a cigarette according to an embodimentwherein a magnetic mesh is incorporated along an outer surface of thefilter rod of the filter element.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

A filter element for a cigarette comprises a cigarette filter materialand at least one magnetic substrate that is incorporated in, on and/oraround the filter material to form the filter element. The cigarettefilter element, which is preferably wrapped in cigarette paper (e.g.,plug wrap), comprises a filter rod of filter material and the magneticsubstrate. The filter element can be attached to a tobacco rod (e.g.,attached with tipping paper) to form a filter cigarette. The at leastone magnetic substrate is adapted to filter (i.e., magnetically attract)ferromagnetic particles such as iron oxide entrained in mainstreamcigarette smoke. A method for producing the filter element is alsoprovided.

The term “mainstream” smoke refers to the mixture of gases passing downthe tobacco rod and issuing through the filter end, i.e., the amount ofsmoke issuing or drawn from the mouth end of a cigarette during smokingof the cigarette. The mainstream smoke contains smoke that is drawn inthrough both the lighted region, as well as through the cigarette paperwrapper. Nanoscale particles incorporated that are incorporated into thetobacco rod and/or cigarette paper of a cigarette (e.g., nanoscaleparticles of iron oxide) may be entrained in mainstream smoke duringsmoking.

The term “magnetic substrate” as used herein refers to a monolithicmagnetic material having at least one dimension of at least 1 mm. Forexample, a magnetic substrate can comprise one or more magnetic beads.Preferred magnetic beads can have an average particle size of greaterthan 1 mm (e.g., at least 2, 3, 4 or 5 mm). The shape of the magneticbeads can be substantially spherical or non-spherical. A magneticsubstrate can have any shape suitable for incorporation in a filterelement. A magnetic substrate can be, for example, a disc, ring, ribbon,mesh, rod or cylinder. As is recognized by one with ordinary skill inthe art, the size and shape of the at least one magnetic substrate canbe selected so as to incorporate the at least one magnetic substrateinto the filter element. A filter element can comprise one or moremagnetic substrates.

In embodiments where the magnetic substrate is a rod or cylinder,preferably the length of the rod or cylinder is greater than 4 times thediameter.

As mentioned above, the magnetic substrates preferably comprise at leastone dimension greater than 1 mm. Generally, the field strength of amagnet made from a particular magnetic material is proportional to themagnet's size (e.g., volume). Preferred magnetic substrates are sizedand shaped to be effective filters for ferromagnetic particles when themagnetic substrates are incorporated in the filter element of acigarette.

Magnetic materials are well known and the cigarette filter element cancomprise at least one magnetic substrate made from any magnetic materialcapable of filtering ferromagnetic particles. The magnetic substrate cancomprise an electromagnet or a permanent magnet. In an exemplaryembodiment, the magnetic material used to form the magnetic substrate isselected from the group consisting of ferrite magnets (e.g., magneticcompositions comprising iron oxide and strontium oxide or barium oxide),neodymium iron boron (NdFeB) magnets, samarium cobalt magnets (e.g.,SmCo₅, Sm₂Co₁₇, etc.), aluminum nickel cobalt magnets (e.g., alloys ofaluminum, nickel, cobalt and iron) and mixtures thereof.

Ferromagnetism is a phenomenon by which a material can exhibit aspontaneous magnetization. Ferromagnetism manifests itself in the factthat an externally imposed magnetic field can cause the magnetic domainsto line up with each other which, in turn, magnetizes the material.

The thermal response of magnetic materials is well understood. As isknown to those having ordinary skill in the art, the spontaneousmagnetization within a magnetic material decreases with increasingtemperature. The temperature above which spontaneous magnetizationcannot occur in a magnetic substrate is known as the Curie temperature.Accordingly, the range of effective filtration temperatures of themagnetic substrate is below its Curie temperature. The Curie temperatureof neodymium iron boron magnets is typically in the range of about 300to 350° C. Samarium cobalt magnets and aluminum nickel cobalt magnetstypically have a Curie temperature in the range of about 750 to 800° C.,and about 800 to 900° C., respectively. Preferably the magneticsubstrates that are incorporated in the filter element have a Curietemperature sufficiently high to retain their magnetic properties duringthe smoking of a cigarette. In a preferred embodiment, the at least onemagnetic substrate has a Curie temperature of greater than about 300° C.

The magnetic substrate can be fully or partially dense. The magneticsubstrate can comprise a monolith having 100% or less of its theoreticaldensity (e.g., a substrate that is about 50, 60, 70, 80 or 90% dense).The magnetic substrate can be in the shape of a fully dense ring or discof magnetic material, or the magnetic substrate can be in the shape of aporous ring or disc (e.g., frit). In a further embodiment, the magneticsubstrate can comprise an electromagnet. Ferromagnetic particles can befiltered from mainstream smoke via magnetic attraction to the at leastone magnetic substrate that is incorporated in the filter element. Thefilter material (e.g., cellulose acetate) that comprises the bulk of thefilter element is preferably not magnetic.

Cigarette filters are made in a variety of designs. Typically, cigarettefilters comprise four main components: a filter tow such as a bundle ofcellulose acetate fibers or paper that comprise the bulk of the filter;a plasticizer (i.e., a softening agent added to bind the filter fiberstogether into a filter rod); a plug wrap (i.e., a paper wrapper that isused to contain the filter material); and an adhesive used to secure theplug wrap to the filter rod.

Cigarette filter rods are commonly made from filamentary materials. Apreferred filamentary material is cellulose acetate, which is acellulose ester. Cigarette filter rods can also be made from othercellulose ester fibers (e.g., cellulose triacetate), regeneratedcellulose (e.g., rayon), polyamide fibers (e.g., nylon), polyimidefibers, acrylic fibers, polyester fibers, polycarbonate fibers,polyethylene fibers, polyvinyl chloride fibers, filamentary polyolefinmaterials, polypropylene fibers, wood pulp fibers, cotton, flax, jute,wool, silk, ramie, protein fibers and paper. Cigarette filter rods canbe formed from combinations of these materials.

Filter rods for making cigarette filters, which can be attached totobacco rods to produce filter cigarettes, can be made by forming abundle or tow of the filter material into a rod using a rod formingapparatus. Typically, a filter rod comprises from about ten to thirtythousand filaments of the filter material. Conventionally, a plasticizeror binder such as triacetin is added to the tow before it is passed intothe rod forming apparatus. Furthermore, the tow can be spread andfluffed up, or “bloomed,” usually by placing the tow under tension andpassing it over air jets. The bloomed tow can be passed through a funnelor other constricting device and then through a shaped aperture to formthe filter rod.

The plasticizer, which can be added to the tow during or after bloomingcan enhance the bonding of the filaments to each other at theircross-over points when the tow is gathered. Addition of a plasticizercan increase the firmness of the filter rod formed from the tow. Theplasticizer may also have filtration properties. The attributes of thefinished filter rod (e.g., filtration efficiency, firmness, dimensionalstability, etc.) can be improved by curing (e.g., heating) theplasticizer.

The filter rod can be provided with an outer layer (e.g., plug wrap) tomaintain its shape. The outer layer can comprise a wrapping of cigarettepaper or other sheet material. As explained below, a magnetic substratecan be incorporated into the filter rod such that the magnetic substrateis substantially surrounded by the filter material, or, in analternative embodiment, a magnetic substrate can be incorporated into aspace or cavity within the filter rod. In yet a further embodiment, amagnetic substrate can be formed wholly or partially around the filterrod.

Various filter constructions including any conventional or modifiedfilter known in the art can be used to form the filter element thatcomprises a magnetic substrate. Exemplary filter structures include, butare not limited to, a mono filter, a dual filter, a triple filter, acavity filter, a recessed filter, a free-flow filter or combinationsthereof. Mono filters typically contain cellulose acetate tow orcellulose paper materials. Pure mono cellulose filters or paper filterprovide good tar and nicotine retention, and are highly degradable. Dualfilters typically comprise a cellulose acetate mouth end and a purecellulose or cellulose acetate segment. The length and pressure drop ofthe segments in a dual filter can be adjusted to provide the desiredfiltration (i.e., adsorption and/or absorption) and resistance to draw(RTD). Triple filters can include mouth and tobacco side segments, and amiddle segment comprising paper. Cavity filters typically have twosegments, e.g., acetate-acetate, acetate-paper or paper-paper, separatedby a cavity. Recessed filters include an open cavity at the mouth end.The filter element can be ventilated and/or comprise additionalfiltration media (e.g., activated carbon), flavorings, catalysts orother additives suitable for use in a filter element. According toembodiments, the magnetic substrate can be combined with filter materialused to form a filter rod and/or with a pre-formed filter rod to formthe filter element. The filter element can, in turn, be incorporatedinto a cigarette.

The magnetic substrate can be incorporated into one or more cigarettefilter parts selected from the group consisting of a shaped paperinsert, a plug, a space between plugs, cigarette filter paper, acellulose acetate sleeve, a polypropylene sleeve, and a free-flowsleeve.

The filter element, which can be attached to a tobacco rod to form afilter cigarette, can be constructed so that the magnetic substrate isadapted to filter ferromagnetic particles from the mainstream smoke of acigarette comprising the filter element. Preferably a magnetic substratecan substantially reduce the amount of ferromagnetic particles (e.g.,nanoscale ferromagnetic particles) issuing from the mainstream smoke ofthe cigarette. A preferred filter element comprising the at least onemagnetic substrate can reduce the amount of ferromagnetic particles inmainstream smoke by at least about 10% (e.g., at least 20, 30, 40, 50%or more).

The at least one magnetic substrate, in addition to removingferromagnetic particles from mainstream smoke, can optionally affect theorganoleptic properties (e.g., aroma and/or taste) of mainstream smoke.The at least one magnetic substrate can change the chemical compositionof mainstream gas that flows through a filter element comprising themagnetic substrate. For example, the magnetic substrate can catalyze theconversion of at least one gas phase constituent. A catalyst is capableof affecting the rate of a chemical reaction without participating as areactant or product of the reaction.

Aspects of incorporating the at least one magnetic substrate into filtermaterial and/or a filter rod to form the filter element are discussedbelow.

A magnetic substrate can be incorporated into the filter element in anumber of ways. The magnetic substrate may be incorporated into thefilter material before, during and/or after its manufacture into afilter rod. For example, a magnetic substrate can be incorporated intoraw filter material or into a complete filter rod.

A magnetic substrate or plurality of substrates can be incorporateddirectly into the filter material used to form the filter rod. Thedistribution of the at least one magnetic substrate in the filterelement can be homogeneous or non-homogeneous. In alternate embodiments,the at least one magnetic substrate can be evenly or unevenlydistributed throughout the filter rod. For example, the magnetic beadscan be more heavily loaded at the tobacco rod end, mouth end, or in theintermediate region between the tobacco rod end and the mouth end of thefilter rod.

In an embodiment, one or more magnetic substrates can be employed in ahollow portion of a cigarette filter element. For example, somecigarette filters have a plug/space/plug configuration in which theplugs comprise a fibrous filter material and the space is simply a voidbetween the two filter plugs. That void can be filled partially orwholly with one or more magnetic substrates. The magnetic substrate cancomprise a gas permeable monolith such as a porous disc. A packed bed ofmagnetic substrates can be incorporated into such a void. A bed ofmagnetic beads can be located in a space between plugs of a standardcellulose acetate filter rod.

A magnetic substrate or plurality of substrates can be incorporated in afilter rod after the filter rod has been formed. As a non-limitingexample, a magnetic substrate can be formed around a pre-formed filterrod. A magnetic ring, for example, can be formed (e.g., crimped) arounda pre-formed filter rod such that the ring has an outer diameter that isapproximately equal to the diameter of the filter rod. The radialthickness and the axial width of a magnetic ring can range from about0.05 mm to 1 mm or more. For example, a magnetic ring can have athickness and/or a width of at least about 0.1, 0.2, 0.5, 1 or 2 mm.

By way of a further example, a magnetic substrate can be formed on anexterior surface of a pre-formed filter rod before the rod is wrapped incigarette paper to form the filter element. Magnetic rods or strips, forexample, can be arranged axially along an exterior surface of a filterrod, between the filter rod and the cigarette paper formed around thefilter rod.

In yet a further example, a sheet of magnetic substrate (e.g., magneticfoil) can be formed around a filter rod that is in turn wrapped incigarette paper to form the filter element, or the sheet can be firstcombined with the plug wrap to form a laminate that is wrapped aroundthe filter rod to form the filter element. An adhesive can be used tosecure the magnetic substrate to the filter rod and/or the plug wrap.Preferably, a magnetic foil-laminated plug wrap is adapted to be formedaround a filter rod such that the magnetic foil is positioned on theinner surface of the plug wrap (e.g., in contact with the filtermaterial).

The magnetic substrate(s) whether blended directly with the filtermaterial, incorporated as a packed bed, or incorporated after formationof a filter rod, may be used alone in the filter element or may beincorporated with other known materials having gas phase activity suchas activated carbon, flavorants and the like.

In all such filter element configurations the resistance to draw (RTD)of the filter element comprising the at least one magnetic substrate ispreferably less than about 5 inches of water when measured at an airflow velocity of about 1050 cc/min.

A further embodiment provides a cigarette having a cigarette filterelement, wherein the filter element comprises a filter material and amagnetic substrate. The magnetic substrate is capable of filtering(i.e., via magnetic attraction) ferromagnetic particles from themainstream smoke of the cigarette.

Techniques for cigarette manufacture are known in the art. Anyconventional or modified cigarette making technique may be used toincorporate the magnetic substrate. The resulting cigarettes can bemanufactured to any known specifications using standard or modifiedcigarette making techniques and equipment.

Cigarettes may range from about 50 mm to about 120 mm in length. Thecircumference is from about 15 mm to about 30 mm in circumference, andpreferably around 25 mm. The tobacco packing density is typicallybetween the range of about 100 mg/cm³ to about 300 mg/cm³, andpreferably 150 mg/cm³ to about 275 mg/cm³.

In cigarette manufacture, the tobacco is normally employed in the formof cut filler, i.e., in the form of shreds or strands cut into widthsranging from about 1/10 inch to about 1/20 inch or even 1/40 inch. Thelengths of the strands range from between about 0.25 inches to about 3.0inches. The cigarettes may further comprise one or more flavorants orother additives (e.g., burn additives, combustion modifying agents,coloring agents, binders, etc.) known in the art.

Any suitable tobacco mixture may be used for the cut filler. Examples ofsuitable types of tobacco materials include flue-cured, Burley, Bright,Maryland or Oriental tobaccos, the rare or specialty tobaccos, andblends thereof. The tobacco material can be provided in the form oftobacco lamina, processed tobacco materials such as volume expanded orpuffed tobacco, processed tobacco stems such as cut-rolled or cut-puffedstems, reconstituted tobacco materials, or blends thereof. The tobaccocan also include tobacco substitutes.

Yet another embodiment provides a method of smoking the cigarettedescribed above, which involves lighting the cigarette to form smoke anddrawing the smoke through the cigarette, wherein during the smoking ofthe cigarette, the at least one magnetic substrate filters ferromagneticparticles from the mainstream smoke. Generally, smoking of a cigaretteinvolves lighting one end of the cigarette, which causes the tobaccocontained therein to undergo a combustion reaction while drawing thesmoke produced from the combustion reaction through the mouth end of thecigarette. A cigarette can be smoked by other means, however, such as byusing an electrical heater as described, for example, incommonly-assigned U.S. Pat. No. 6,053,176; 5,934,289; 5,591,361 or5,322,075, each of which is incorporated herein by reference in itsentirety. In embodiments where the magnetic substrate is anelectromagnet, an electrical heated can be used to delivery an electriccurrent to the electromagnet in order to magnetize the electromagnet.

The following examples are illustrative. In an embodiment, magneticbeads can be incorporated into the filter material of the cigarettefilter element itself. This embodiment is illustrated in FIG. 1, whichshows a cigarette 2 comprised of a tobacco rod 4 and a filter element 6.The filter element 6 can comprise a tube or solid piece of material suchas cellulose acetate fibers 8 having magnetic beads 10 dispersedtherein. The magnetic beads can be supported by the cellulose acetatefibers. The tobacco rod 4 and the filter element 6 can be joinedtogether with tipping paper (not shown).

In a further embodiment, magnetic beads can be incorporated into thefilter element as a gas permeable bed. FIG. 2 shows a cigarette 2comprised of a tobacco rod 4 and filter element 6. This arrangement issimilar to that of FIG. 1 except the magnetic beads 10 are incorporatedin a space 20 of the filter element. Preferably, space 20 is free ofcellulose acetate. As in Example 1, the tobacco rod 4 and filter element6 can be joined together with tipping paper (not shown).

Another exemplary embodiment of a cigarette is shown in FIG. 3.Cigarette 2 comprises tobacco rod 4 and filter element 6. The filterelement further comprises at least one magnetic ring 30 that is disposedradially around the filter rod. The thickness of the magnetic ring ispreferably about 1 mm, and can be any suitable axial length that is lessthan the length of the filter rod. The tobacco rod 4 and the filterelement 6 can be joined together with tipping paper (not shown).Further, the filter element 6 may include a filter overwrap (not shown).Preferably the magnetic ring is external to the filter rod and thefilter overwrap is wrapped around both the filter rod and the magneticring.

Other exemplary embodiments of a cigarette are shown in FIGS. 4-5.Cigarette 2 comprises tobacco rod 4 and filter element 6. In FIG. 4 thefilter element further comprises magnetic rods 40 that are arrangedaxially along the length of the filter element. In FIG. 5 the filterelement further comprises magnetic rods 50 that are arranged axiallyalong the length of the filter element. In FIG. 4, the magnetic rods areexternal to the filter rod 44 and a filter overwrap 46 is wrapped aroundboth the filter rod and the magnetic rods. In FIG. 5, the magnetic rods50 are disposed axially within the filter rod such that the filtermaterial substantially surrounds the magnetic rods.

A further exemplary embodiment of a cigarette comprising a magnetic meshis shown in FIG. 6. Cigarette 2 comprises tobacco rod 4 and a magneticmesh 60 external to the filter rod. A filter overwrap is preferablywrapped around both the filter rod and the magnetic mesh.

A magnetic substrate, such as one or more magnetic rods, can beincorporated into the filter material such that the filter materialsubstantially surrounds the magnetic substrate.

A magnetic substrate may be incorporated into more than one component ofa filter element such as by being incorporated into a void space as abed of packed particles and being incorporated around the filter rod asa sleeve or ring.

The size, distribution and position of the at least one magneticsubstrate incorporated in the filter element either by way ofincorporation directly into and/or on filter material can be determinedthrough routine experimentation from the amount of ferromagneticconstituents in the tobacco smoke, the amount of constituents to beremoved from the mainstream smoke (e.g., trapped by the magneticsubstrate in the filter element), and the magnetic strength of themagnetic substrate.

A still further embodiment relates to a method of making a filterelement comprising a magnetic substrate. The method comprises providinga filter material and plug wrap material; incorporating at least onemagnetic substrate in and/or on at least one of the filter material andplug wrap material; and wrapping the filter material in the plug wrapmaterial to form the filter element.

In preferred embodiments the magnetic substrate can be incorporated inthe filter material prior to forming the filter material into the filterrod or after forming the filter material into the filter rod. Forexample, the at least one magnetic substrate can be formed around (e.g.,crimped around) and/or on an exterior surface of the filter rod prior towrapping the filter rod in the plug wrap.

Provided is a filter material to which a magnetic substrate isincorporated in, on and/or around to form the filter element. Themagnetic substrate can be incorporated in and/or on the filter materialused to form a filter rod, or the magnetic substrate can be incorporatedon and/or around filter material that has already been formed into afilter rod. Optionally, the filter element can be wrapped in paper andattached to a tobacco rod such as via tipping paper to form a filtercigarette. The magnetic substrate can filter via magnetic attractionferromagnetic particles from the mainstream smoke of a cigarettecomprising the magnetic filter element.

While preferred embodiments have been described, it is to be understoodthat variations and modifications may be resorted to as will be apparentto those skilled in the art. Such variations and modifications are to beconsidered within the purview and scope of the claims appended hereto.

All of the above-mentioned references are herein incorporated byreference in their entirety to the same extent as if each individualreference was specifically and individually indicated to be incorporatedherein by reference in its entirety.

1. A filter element adapted to be incorporated into a filter cigarettewherein the filter element comprises a filter material and at least onemagnetic substrate.
 2. The filter element of claim 1, wherein the atleast one magnetic substrate is selected from the group consisting of adisc, ring, ribbon, mesh, rod, cylinder and spheroid and has at leastone dimension of greater than about 1 mm or greater than about 2 mm. 3.The filter element of claim 1, wherein the at least one magneticsubstrate consists essentially of a ferrite magnet, a neodymium ironboron magnet, a samarium cobalt magnet, an aluminum nickel cobalt magnetor an electromagnet.
 4. The filter element of claim 1, wherein the atleast one magnetic substrate comprises sintered material which is atleast 50% dense or at least 90% dense.
 5. The filter element of claim 1,wherein the at least one magnetic substrate has a Curie temperature ofat least about 300° C. and/or a magnetic field strength effective toattract ferromagnetic and/or nanoscale particles being carried by themainstream smoke of a cigarette comprising the filter element.
 6. Thefilter element of claim 1, wherein the filter material is wrapped inplug wrap and the at least one magnetic substrate is a ring disposed onan inner surface of the plug wrap.
 7. The filter element of claim 1,wherein the at least one magnetic substrate is (a) incorporated in thefilter material (b) is non-homogeneously dispersed throughout the filtermaterial, and/or (c) is formed at least partially around the filtermaterial.
 8. The filter element of claim 1, wherein the filter materialis wrapped in plug wrap and the at least one magnetic substrate isdisposed on an inner surface of the plug wrap and/or the at least onemagnetic substrate is adhered to an inner surface of the plug wrap withan adhesive.
 9. The filter element of claim 1, wherein the at least onemagnetic substrate is incorporated into one or more filter partsselected from the group consisting of a shaped paper insert, a plug, aspace between plugs, cigarette filter paper, a cellulose acetate sleeve,a polypropylene sleeve and a free-flow sleeve.
 10. The filter element ofclaim 1, wherein the resistance to draw through the filter element isless than about 5 inches of water at an air flow velocity of about 1050cc/min.
 11. The filter element of claim 1, wherein the filter elementcomprises a mono filter, a dual filter, a triple filter, a cavityfilter, a recessed filter, a free-flow filter or combinations thereof,wherein the filter material is selected from the group consisting ofcellulose ester fibers, regenerated cellulose, polyamide fibers,polyimide fibers, acrylic fibers, polyester fibers, polycarbonatefibers, polyethylene fibers, polyvinyl chloride fibers, filamentarypolyolefin materials, polypropylene fibers, wood pulp fibers, cotton,flax, jute, wool, silk, ramie, protein fibers, paper and mixturesthereof.
 12. The filter element of claim 1, wherein the filter elementfurther comprises at least one additive, wherein the additive isselected from the group consisting of an adsorbent, flavorant andcatalyst.
 13. A cigarette comprising the filter element of claim
 1. 14.The cigarette of claim 13, wherein the at least one magnetic substrateis adapted to reduce the amount of ferromagnetic particles entrained inthe mainstream smoke of the cigarette by at least 10% and/or to changethe chemical composition of mainstream smoke that flows through thefilter element.
 15. The cigarette of claim 13, wherein the cigarettecomprises a tobacco rod wrapped in cigarette paper, said tobacco rodattached to the filter element with tipping paper, and the at least onemagnetic substrate is incorporated axially between the filter materialand the tobacco rod.
 16. The cigarette of claim 15, wherein the tobaccorod and/or cigarette paper further comprises nanoscale and/orferromagnetic particles.
 17. A method of making a cigarette filterelement comprising at least one magnetic substrate, comprising:providing a filter material and plug wrap material; forming the filtermaterial into a filter rod; incorporating the at least one magneticsubstrate in and/or on at least one of the filter rod and plug wrapmaterial; and wrapping the filter rod in the plug wrap material to formthe filter element.
 18. The method of claim 17, wherein the magneticsubstrate is incorporated in the filter material prior to forming thefilter material into the filter rod.
 19. The method of claim 17,comprising forming the at least one magnetic substrate (a) at leastpartially around the filter rod prior to wrapping the filter rod in theplug wrap, (b) on an exterior surface of the filter rod prior towrapping the filter rod in the plug wrap, and/or (c) on an interiorsurface of the plug wrap prior to wrapping the filter rod in the plugwrap.